Presentation
Background Reflectance Affects Estimates of Automotive Window Tint Transmittance Levels
SessionFOR2: Forensic Professionals
DescriptionGiven that a number of US states treat window-tint light transmittance as a primary offense, understanding how accurately observers can visually estimate tint transmittance seems prudent. From all the potential factors that could affect estimates, we manipulated background reflectance to simulate vehicles with darker versus lighter interiors. We used three reflectance levels of 11.1% (“dark”), 35.6% (“medium”), and 76.0% (“light”), six tint-transmittance levels (5%, 19%, 30%, 34%, 42%, and 49%) along with a 76% “no-tint” control, and a common legal/illegal demarcation of 28%. Twenty-seven subjects, naïve to the number of tint levels or different backgrounds, viewed the tint-background combinations and provided window-tint light-transmittance values on a 0% (none) to 100% (clear glass) scale. We found that background reflectance affected all but the darkest tints. Subjects correctly rated the control tint as legal and the two darkest tints as illegal. Importantly, half of the legal tints were rated illegal with a medium background, and all were rated illegal with a dark background. Our findings suggest that observers’ ability to accurately classify window tint as legal or illegal should be called into question, and that the use of window-tint transmittance estimates as a primary basis for stopping motorists should be reconsidered.
Event Type
Lecture
TimeTuesday, October 20th4:50pm - 5:10pm PDT
Location